The research on the nondestructive inspection technologies is quite important for the development of industry and trade. These techniques play important roles in the industrial quality management and in the agricultural pest quarantine. For example, in the agriculture, after entering the World Trade Organization (WTO), several countries need the accurate quarantine for the agricultural products and the associated technologies after adopting the globalization. Although the traditional sampling operated by human and the microscopic anatomy inspections are effective, the human errors often occurred under the pressure of fast custom clearance. Besides, it is hard to distinguish whether the surface damage of the fruits is made by the collision or by the pest, and the long-term experiences are necessary for the correct judgment. However, if the perspective images of the internal parts of the fruits acquired by the nondestructive methods are available as the objective quarantine standards, the impact of the damage of pests on agriculture and ecosystem can be avoidable.
Regarding the nondestructive inspection methods, the most frequently used one is X-ray. Therefore, the X-ray tomography becomes one of the most important technologies for the nondestructive methods. When the internal features of the inspected object are complicated or even overlapped and intervened, the general planar scanning cannot provide sufficient resolutions. The tomography can make up this insufficiency and provide the more detailed information to the users. For the industrial applications, the quality control engineer can clearly indentify the internal structures to improve the yield rate; for the agricultural applications, the quarantine officials can easily observe the detail symptoms or the canals bored by the pests. Therefore, the invasion of the alien pests can be avoided, and the edible security can be improved.
However, not every type of the X-ray machines can perform the tomography. Moreover, there are some problems of the professional computerized tomography machines including the mammoth dimensions, expensiveness and unavailability to some operation places.
Please refer to FIG. 1, which is the schematic diagram showing the computerized tomography machine of the prior art. The tomography machine 1 includes a bed 10 set up on the floor, and the object 2 to be inspected is disposed on the bed 10. In FIG. 1, the object 2 to be inspected is a person. The tomography machine 1 further includes an emitter head 14 and the sensing element 16, both of which are configured on the rotating rack 12b, which in turn is pivotally configured on the stand 12a. Usually, there is a motor inside the stand 12a for rotating the rotating rack 12b, and the stand 12a is set up on the floor by means of the foundation 12. The tomography machine 1 can obtain the absorption curves of the object 2 with 360 degrees through the rotation of the rotating rack 12b. These signals are used for the reconstruction of the crossing section images. Since the images are based on the object 2, the geometric central axis must be aligned to superimpose the rotating axis 100. Accordingly, the emitter head 14 and the sensing element 16 can accurately rotate around the geometric central axis of the object 2, so the object 2 can be exposed within the irradiation area of the X-ray.
It can be seen from FIG. 1 that the mammoth dimensions of the computerized tomography machine 1 majorly results from the bed 10 and the rotating rack 12b, which occupies the most space. Due to the rotation of the rotating rack 12b, no article can be disposed in the space swept by the rotating rack 12b, otherwise the collisions between the article and the emitter head 14 or between the article and the sensing element 16 will occur. Thus, in order to install the tomography machine 1, the accommodated space can not be too small. However, for the production lines of the products or for the packaging lines and the conveyer belts of the fruits and vegetables, the conventional tomography machine 1 is too big. Furthermore, during the tomographing, the object 2 is moving along the rotating axis 100 so as to obtain the images of 360 degrees in different sections of the object 2. For the human body as the object 2, these sections include chest, head, abdomen, etc. However, the moving way of the object 2 is not applicable to the operation of the production lines. Moreover, the location of the object 2 may interfere with the conveyer belt of the production line, and this condition would cause the inaccurate result of the tomography. In addition, since the dimensions of the emitter head 14 and the sensing element 16 are mammoth, the rotating speed thereof is slow, and it is not cost-effective and applicable for the production lines where the efficiency is highly emphasized.
In order to solve the above mentioned problems, the development team of the present invention has done a lot of analyses on the drawbacks of the conventional technologies. Finally the portable inspection apparatus for x-ray tomography is invented and is able to overcome the drawbacks of the conventional technologies.